The overall objective of this study is to evaluate the efficacy of islet allotransplants for labile diabetes mellitus in patients who do not meet standard inclusion/exclusion criteria for any other islet transplant trials in the US and are not good candidates for a pancreas transplant. We expect that this will include patients who have surgical diabetes (total pancreatectomy) rather than type 1 diabetes, patients who are highly sensitized (PRA>20%), and patients who have had prior failed pancreas transplantation. These patients may have equally severe hypoglycemia, glucose lability, and/or severe microvascular complications, but are excluded from standard islet transplant trials currently available in the U.S.